1. Field of the Invention
The present invention relates generally to a turbine housing and more specifically to a turbine housing arrangement which permits the overall dimensions of the device to be reduced without any loss in production ease.
2. Description of the Prior Art
FIGS. 1 and 2 show an example of a prior art turbine housing arrangement 1 which forms part of an automotive turbocharger (viz., a supercharger driven the exhaust gases expelled from the combustion chambers of the engine). This arrangement as shown, includes a variable nozzle 2 for deflecting the exhaust gases which flow from engine in a manner which permits the capacity of the turbine arrangement to variable and the permit high efficiency during both high and low engine speed operation.
Examples of such an arrangement are disclosed in copending U.S. Pat. No.4,678,397 Hiroshi Komatsu et al. The content of this application is hereby incorporated by reference thereto.
However, in order to facilitate easy manufacture, the axes (OA, OB, OC) of (a) the turbine impeller 3, (b) the exhaust port 4 formed in the cover which closes an aperture 5 formed in the housing 6 for the purposes of inserting the impeller 3 and variable nozzle arrangement 2, and (c) the just mentioned aperture 5 have been arranged to coincident as shown. Previously this has been deemed particularly necessary in order to facilitate the precision machining of the surface 7 over which the tongue or vane member 8 of the variable nozzle sweeps--a measure necessary to permit the deflecting vane or tounge 8 to closely juxtapose the wall of the housing 6 and limit the amount of exhaust gas which can leak therebetween.
Accordingly, as will be appreciated from FIG. 1 of the drawings the attachment flange 9 formed at the periphery of the housing is inherently required to extend radially outwardly thus increasing the overall dimensions of the arrangement. Thus, this arrangement encounters the drawback of being bulky and thus difficult to arrange in the very crowded engine compartment of currently produced automotive vehicles.